Thermographic instruments are commonly used to obtain thermographic profiles of subjects such as industrial machines or components of operating equipment. Inspecting a subject's thermographic profile can reveal whether a failure is imminent or a machinery adjustment is necessary. This information may be employed to direct maintenance efforts and to prevent unplanned shutdowns.
Inspecting a subject's instantaneous thermographic profile, however, may not provide sufficient information. For example, a subject may have an expected base-line thermographic profile and the subject's thermographic profile may vary from this base-line thermographic profile due to changes in operating conditions or environment. Such changes in operating conditions may include short-term load variations, ambient temperature variations, and power fluctuations. Variations in the subject's thermographic profile may be expected due to normal variations of these and other operating conditions. However, large variations in operating conditions, failures, component drift, long-term changes in operating conditions, and other conditions may lead to large changes to the subject's thermographic profile. Such changes may lead to unsafe and/or life-threatening situations.
Distinguishing abnormal thermographic profiles from a base-line thermographic profile and from normal thermographic profile variance may be difficult. Detecting abnormal thermographic profiles is further complicated when monitoring a subject over a lengthy duration, monitoring a large number of subjects, monitoring a subject having a relatively large normal range of thermographic profile variation, and/or the like.